Manufacture of nickel-steel



a citizen of the United States, residin warren STATES PATENT. oFFicE.

PERCY FOOTE COWING-,'0F NEW YORK, N. Y., ASSIGNOR 0F ONE-HALF TO HOWARDFIELD CALPPELL, OF NEW YORK N. Y.

. MANUFACTURE OF 'NICKEL-STEEL;

N 0 Drawing.

To all whom it may concern:

Be it known that I, PERCY Foo'rn Cowmc,

at New York, in the county of New ork, State of New York, have inventedcer-' tain new and useful Improvements in Manufacture of Nickel-Steel;and I do hereby declare the following to be a full, clear, and exactdescription of. the invention, such as will enable others skilled in theart to which it appertains to make and use the same.

The present invention relates to the manufacture of nickel steel byintroducing the nickel in the form of a product obtained as a cathodedeposit in an electrolytic process of refining nickel copper matte. Inthe manufacture of nickel steel by combining steel and metallic nickel,it has been found very difficult to incorporate the nickel uniformly soas to secure a homogeneous alloy free from flaws or hollows.

I have found, that, by substituting for' nickel, in the customaryprocess 'of producing nickel steel alloys in a crucible, open hearth orelectric furnace, the nickel-iron material obtained as a cathode depositin an electrolytic process of refining nickelcopper matte, the oxidationof the -nickel which is one of the difficulties in the ordinaryproduction of nickel steel is reduced to a minimum.

In the practice of the invention, anickel iron material obtained-as acathode deposit in the electrolytic separation of copper and nickel fromcopper-nickel compounds may be used. Such nickel-iron material may beobtained from a nickel-copper matte produced in accordance with theusual practice.

- The nickel-copper mattes, as obtained from the ore by smelting,contain considerable iron, and-it is therefore desirable to subject thesmelter-matte to bessemerizing or similar treatment in order thereby todiscard as muchiron as practicable so as to produce a matte high innickel and copper and low in iron. Ithas been found that the iron seldomexceeds one per cent. Inthe preferred practice, the bessemerized matteis then subjected to an oxidizing roast to practically eliminate sulfur,and is' thereafter. reduced to a nickel-copper alloy whose relativeproportions of nickel and copper will vary with the relative proportionsof these metals in the ores from which the matte is de- Specification ofLetters Patent.

Patented flct. 19, 1920.

Application filed June 16, 1920. Serial No. 389,478.

rived. Thus, forinstance, in' some cases the nickel-copper alloy willcontain approximately 50% nickel and 50% copper, or it mayhave as low apercentage as 25% or thereabout, the nickel being then approximately75%. These percentages are illustrative only and they may vary widely.Should it be found desirable to decreasethe percentage of copper in thenickel-copper alloy to be used as an anode, the bessemerized matte issubjected first to a partial roast, and is then leached withjdilutesulfuric acid in order to dissolve out and remove a part of the copper.The leached residue may then be reduced to form a nickel-copper alloy,still'containing a notable percentage of sulfur; or, should it bedeanodes is then treated in such manner as to replace the copper by,iron, or by nickel and iron; as, for instance, by cementation (which Iprefer). or by electrolysis. Nickel and iron in the solution thusobtained may then be electrolytically deposited upon a suitable cathode.Should cobalt be present the nickel-iron in the cathode deposit, andwould accompany the nickel-iron into the finished steel.

As an instance of one way of practising the invention, I may recite theresults 0btained starting with anodes containin approximately 68% ofnickel and 27 %o copper. The dissolving electrolyte employed was asolution of ferrous chlorid and nickel chlorid of a specific gravityofabout 1.15,

and was used at a temperature of about 70 C. The relative proportion of,ferrous chlorid to nickel chlorid in this electrolyte was such that theratio of the iron to the nickel was as 16 to 84. Under these conditions,on the passage of the current, nickel and copper of the anodes went intosolution The solution conin thissolution it would be associated with ingnickel and iron therefrom upon a suitable cathode, and was then reusedas the dissolving electrolyte thus completing a cycle. In this instance,the current density,

at anode and cathode, was about amperes to the square foot, both for thedissolving electrolyte and for the depositing electrolyte. Thenickel-iron product, suitable for addition to steel in appropriateproportion,

in accordance with the invention, contained approximately 84% of nickeland 16% of iron. I

The resulting cathode material, comprise ing nickel and iron. intimatelyassociated, is then used in the place of nickel in the customary processof producing nickel steel in a crucible or furnace. The intimaterelation of the molecules of nickel. and iron in the deposited cathodeproduct is such that I have found that this product may serve to greatadvantage in the manufacture of nickel steel. The cathode product is ofmaterially lower melting point than nickel, and, by reason of this lowermelting point, dissolves readily in the molten steel inthe furnace, orit may be added as the steel is drawn, into the ladle, thus minimiz ingthe oxidation of the nickel, which is one of the difficulties in theordinary production of nickel steel in the open hearth furnace. So,also, the particles of the two metals, nickel and iron, being intimatelyassociated, throughout the entire mass of the cathode product, it iseasier to alloy the product with a bath of steel than if nickel only hadbeen used; also in the manufacture of steel by the crucible process, itis correspondingly easier to obtain an intimate and ready fusion of theentire contents .of the crucible into a homogeneous nickel steelproduct.

One of the advantages, moreover, of the process is that the cathodematerial is entirely free from carbon, silicon, and oxygen, whilephosphorous, sulfur and other like impurities, if present at all, are invery 'small amounts.

tained, and incorporating the resultant nickel-iron product with steelfor producing nickel-steel; substantially as described.

2; The method' of producing nickel-steel, which comprises roastingbessemerized nickel-copper matte, leaching out a portion of the coppertherefrom, producing nickelcopper alloy from the leached residue,dissolving sa-id alloy electrolytically to form a solution containingnickel and copper, substituting iron, or nickel and iron, for the copperin said solution, electrolytically depositing nickel iron from thenickel-iron solution thus obtained, and incorporating the resultantnickel-iron product with steel for producing nickel-steel; substantiallyas described.

3. The method of producing nickel-steel, which compriseselectrolytically dissolving a nickel-copper alloy obtained fromnickelcopper matte to form a solution containing nickel and" copper,substituting iron, or nickel and iron, for the copper in said solution,electrolytically depositing nickel-iron from the nickel-iron solutionthus obtained, and incorporating the resultant nickel-iron product withsteel for producing nickel steel; substantially as described.

PERCY FOOTE COWING.

